Ok guys, I had the same problem, which I found a fix to. I mean, I just bought an Alienware and it can't even run Tekkit? You've no idea how pissed I was lol. Anyways- Go to %appdata% and delete the .techniclauncher folder. Be sure to back up your world saves ((((((((FIRST)))))))). Then open the Technic Launcher and set the allocated memory as low as possible (either the 512 mb or the 1g). I know this sounds weird, but Java is an odd beast. I was running it at 20 fps at best to start with and now I'm up to 125. I hope this helped you guys, I know how incredibly frustrating it was to have the game crash and constantly lag. Best of luck and God bless!